Rotary-hook sewing machine



April 29,1930. w. N. PARKES ROTARY HOOK SEWING MACHINE INVENTOR WilliamMParkeJ A TORNEY Filed Aug. 11

i WT-":1 ESSEQ MQ Patented Apr. 29, 1930 UNETED STAE'ES Parser WILLIAMNELSON PAR-KES, OF BROOKLYN, HEX/V YORK, ASSIGNOR TO THE SING-ERMANUFACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEWJERSEY ROTARY-HOOK SEWING MACHINE Application filed August -11, 1927.

This invention relates to improvements in sewing machines of the typeemploying a vertical axis loop-taker to cast needle-thread loops arounda bobbin-carrier journaled in said loop-taker and confined to limitedoscillations about its journal axis.

, The present invention has for its primary object to provide animproved construction for effecting an unobstructed passage for theneedle-thread loops around the bobbincarrier of a vertical axisloop-taker, in so far as said needle-thread loops would meet withinterference or resistance by the means employed for limiting therotation of said carrier.

In accordance with the present improved construction, the bobbincarrier,as usual, has a peripheral bearing rib journaled in a raceway in theloop-taker, substantially as disclosed in my prior United States PatentNo. 1,484,151, Feb. 19, 1924:. Above the'bearing rib the body of thebobbin-carrier is formed, at substantially diametrically oppositepoints, with a notch and a shoulder, the notch being entered by astop-lug depending from the throat-plate and restraining thebobbin-carrier against rotation with the loop taker. The shoulderreferredto is adapted to be engaged by a finger extending laterally fromthe upper end of a vertically disposed rock-shaft jour'naled in abracket detachably secured to the underside of the machine cloth-plateand supporting the rotary loop-taker mechanism asa unit. At its lowerend, said rock-shaft carries a lateral arm yieldingly held by a springagainst an eccenv tric secured upon a loop-taker actuating shaft,journaled beneath the cloth-plate and rotated once for each completereciprocation of the needle of the sewing machine. The loop-takeractuating shaft is journaled, at its forward end, in the detachableloop-taker bracket and is suitably geared with the vertical loop-takershaft to impart two rotations to the loop-taker for each reciprocationof the needle. It will therefore be understood that while the loop-takerperforms a multiple of rotations during each reciprocation'of theneedle, the rock-shaft finger referred to engages the bobbin-carrieronly once for each Serial No. 212,172.

needle reciprocation. As the movements imparted to said finger are veryshort and as its actuating eccentric is comparatively large in diameter,with a correspondingly small degree of eccentricity, it is evident thatthe construction described lends itself well to tion of rotation of theloop-taker, the sudden stopping of the bobbin-carrier by the throatplate stop-lug after oscillation of the carrier by the opener finger,coupled with the minimum of friction referred to, causes anincrease in anatural tendency of'the bobbin to rotate in a direction opposite to thedirection of rotation of the loop-taker and therefore tends to keep thebobbin-thread taut, a condition enhancing the efficiency of thelooptaker. p

In the accompanying drawings, Fig. 1 is a substantially central,longitudinal section of a portion of a sewing machine cloth-plate andits attached loop-taker mechanism bracket, and showing the usualreciprocatory needle at substantially the lower end of itsstroke. Fig. 2is a top-plan view of the same portion of the cloth-plate, but omittingthe throatplate, slide-plates and the feed-dog. Fig. 3 is a bottom plan,on a smaller scale, of the loop-taker bracket. Fig. 4 is a perspectiveview of the loop-taker detached. Figs. 5' and 6 are similar views ofrespectively the looptaker base and thebobbin-carrier. Fig. 7 is aperspective view of the bobbin-carrier auxiliary hook detached. Fig. 8is a bottom plan View of the throat-plate. Fig. 9 is a side provement isshown as embodied in a sewing machine having the usual cloth-plate 1,the throat-plate 2 and, the slide-plates 3 and 4 at opposite sides ofthe throat-plate. Operating through suitable openings in the throatplateare the feed-dog and the reciprocatory needle 6.

Adjustably secured to the underside of the cloth-plate, by screws as 7,is the loop-taker bracket 8 sustaining the loop-taker mechanism in itsassembled form as a detachable unit. Secured by a set-screw 9 in thebracket 8- is a bushing 10, in which is journaled the forward end of theloop-taker actuating shaft 11, which rotates once for each completereciprocation of the needle. The actuating mechanism for the needle andthe shaft 11 may comprise any usual properly timed construction, such asis illustrated, for instance, in the United States patent to J. C.Binge, No. 1,484,191, dated Feb. 19, 1924.

Secured upon the end of the shaft 11 is a bevel-gear 12 which mesheswith a similar gear 13 upon the vertically disposed looptaker shaft 14journaled in suitable bearings provided in the bracket 8. The gears 12and 13 are proportioned to impart two rotations to the shaft 14 for eachrotation of the shaft 11. Detachably connected with the shaft 14 forrotation therewith is the stub-shaft 15 of the inner loop-taker body 16,which is cupped to receive a bobbin-carrier 17. The bobbin carrier 17 isperipherally provided with an interrupted bearing rib 18 journaled in araceway constituted by the flange 19 at the upper edge of the inner body16 and the flange 20 at the upper edge of the outer looptaker body 21secured upon and in peripheral contact with the inner body 16. It is tobe understood that the inner body 16 and the outer body 21 togethercomprise the loop-taker proper, said outer body being formed to providea loop-seizing beak 22 and the inner body being provided with a nose 23disposed rearward of the point of the beak 22 and func tioning todeflect the inner limb-of the needlethread loop into thethread-clearance opening 18 provided by the interruption inthe bearingrib.

The bobbin-carrier 17 is substantially bottomless, its base comprising anarrow bobbinsupporting flange 24 in the present construction formed bya flat ring suitably secured as by soldering or welding to the loweredge of the bobbin-carrier wall; Projecting from the ring or flange 24is'an' auxiliary hook 25 disposedbetween the walls of the innerlooptaker body 16and the bobbin-carrier17, said hook-.25 acting toengage-and rapidly spread the needle-thread loop seized by the looptakerbeak. 22. This feature of the presentconstructionforms the subjectof my patent application Serial No; 212,175, filed August 11, 1927.Sustained within the bobbin-can rierjby the flange-24 is a' bobbin 26 ofany suitableconstruction. Above the bearing rib 1*8Zthe1b0bbin earrier17 is or may be provided with aperturesand a, tension devicesubstantially as described in my prior Patent No. 1,484,151 hereinbeforereferred to, said bobbin carrier body above its bearing rib beingadditionally provided with a notch 27 and a shoulder 28 substantiallydiametrically opposite to the notch 27. The notch 27 is loosely enteredby a stationary stop-lug 29 depending from the throat-plate 2 to confinethe bobbin-carrier to limited oscillation upon its loop-taker journal,it being observed that, the notch 27 is located above and at oneside ofthe thread-clearance opening 18 in the bearing rib 18.

In order to oscillate the bobbin-carrier in a direction opposite to thedirection of rotation of the loop-taker, for the purpose of providing afree thread-passage for the needle-thread loop past the stop-lug 29, theshoulder 28 is intermittently engaged by an opener-finger 30 having ahub 31 suitably secured upon the upper end of a vertically disposedrock-shaft 32. The rock-shaft 32 is journaled in a bearing-bushing33112166. in the bracket 8 and is transversely apertured for thereception of an actuating arm 34 adjustably secured to said rock-shaftby a set-- screw 35. At its free end, the arm 34 is provided with agrooved roller 36 engaging the circular face of a comparatively largeeccentric 37 secured upon the rotary shaft 1 1. Surrounding the bushing33 is a coil-spring 38, one end of whichengages the arm 34 to yieldinglyhold the roller 36 in contact with the eccentric 37, while the other endof the spring 38 enters'an aperture in a collar 39 adjustably securedupon the bushing 33 to vary the tension of the spring. It will beevident from the foregoing description that the opener-finger 30 has arelatively slow motion of approach to the shoulder'28 and is thereforeparticularly suitable for high speed operation of the machine.

As the loop-taker beak 22 is disposed very close to the throat-plate,there is a possibility that in chaining-off, i. e., in the operation ofthe threaded machine in the absence of work, the thread-chain thusformed may sag into the path of movement of the loop-taker beak. Toavoid this contingency, there is provided a segmental, taperingguard-finger 40 over lying the portion of the path first traversed bythe loop-taker beak after seizure of the needle-thread loop. The finger40 extends laterally from its shank 41 adjustably secured by means of ascrew 42 upon the machine frame below the slide-plate 3. The shank 41 isprovided with a needle clearance notch 43, the wall 44 of said notchconstitut ing a stationary abutment for the needlethrea'd loop seizedby'the loop-taker, thereby forcing' the loop more rapidly down theinclinededge of the beak to spread said loop. This guard-finger formsthe subject of my patent issued September 17 1929, under No. 1,728,506.WVhen employing the gua'rd-fim ger in connection with a hemstitchingmachine, it may additionally be provided with a piercer aperture 45.

Having thus set forth the nature of this invention, what I claim hereinis:

1. In a sewing machine, a reciprocatory needle, a vertical-axisloop-taker performing a multiple of rotations during each reciprocationof the needle, a bobbin-carrier journaled in said loop-taker, stationarymeans for restraining said bobbin-carrier against rotation with theloop-taker, a movable finger adapted to impart a short oscillation tothe bobbin-carrier in a direction opposite to the direction of rotationof the loop-taker, and means for actuating said finger to oscillate thebobbin-carrier once only for each needle reciprocation.

2. In a sewing machine, a reciprocatory needle, a vertical axisloop-taker provided with a raceway, a bobbin-carrier having a bodyprovided with a peripheral bearing rib near its top journaled in saidraceway, said bearing rib being interrupted to form a thread-clearancegap, the body of the bobbincarrier above said bearing rib being providedwith a stop-notch disposed at one side of said bearing-rib gap, astationary stop-member positioned to enter said stop-notch to restrainthe bobbin-carrier against rotation with the loop-taker, a bobbin withinsaid bobbin-carrier, and means for slightly oscillating thebobbin-carrier once only for each needle reciprocation in a directionopposite to the direction of rotation of the loop-taker to therebyprovide a free thread-passage past said stop-member.

3. In a sewing machine, a reciprocatory needle, a cloth-plate, a bracketdetachably secured to the underside of said cloth-plate, and aloop-taker mechanism sustained by said bracket for detachment therewithas an assembled unit, said loop-taker mechanism comprising an actuatingshaft rotating once for each needle-reciprocation, a vertical-axisloop-taker shaft performing a multiple of rotations for each needlereciprocation, driving connections between said shafts, a loop takersecured for rotation with said looptaker shaft, a bobbin-carrierjournaled in said loop-taker, an opener-finger adapted to oscillate thebobbin-carrier once only for each needle-reciprocation in a directionopposite to the direction of rotation of the looptaker, and means foractuating said openerfinger from said actuating shaft.

4:. In a sewing machine, a cloth-plate, a reciprocatory needle, avertical-axis looptaker performing a multipleof rotations for eachneedle-reciprocation, a bobbin-carrier journaled in said loop-taker,means for restraining the bobbin-carrier against rotation with theloop-taker, an actuating shaft journaled beneath said cloth-platerotating once for each needle-reciprocation, an openerfinger adapted tooscillate said bobbin-carrier once only for each needle-reciprocation ina direction opposite to the direction of rotation of the loop-taker, avertical-axis rockshaft carrying said finger, and operative connectionsbetween the rock-shaft and said actuating shaft for actuating saidopenerfinger.

5. In a sewing machine, a cloth-plate, a reciprocatory needle, avertical-axis looptaker performing a multiple of rotations for eachneedle-reciprocation, a bobbin-carrier journaled in said loop-taker,means for restraining the bobbin-carrier against rotation, with theloop-taker, an actuating shaft journaled beneath said cloth-platerotating once only for each needle-reciprocation, an openerfingeradapted to oscillate said bobbin-carrier onceonly for eachneedle-reciprocation in a direction opposite to the direction oflooptaker rotation, a vertical-axis rock-shaft carrying said finger, anarm carried by said rock-shaft, an eccentric upon said actuating shaft,and a spring yieldingly holding said arm in operative engagement withsaid eccentric.

6. In a sewing machine, a reciprocatory needle, a vertical-axisloop-taker, a bobbincarrier ournaled in said loop-taker, means forrestraining the bobbin-carrier against ternal raceway around the top ofits side wall, a bobbin-carrier provided with an in terrupted bearingrib journaled in said raceway, said bobbin-carrier having a centrallyopen base constituted by a narrow internal flange provided at the bottomof the bobbincarrier wall, and means for oscillating said bobbln-carrieronce only for each needlereciprocation in a direction opposite to thedirection of loop-taker rotation.

In testimony whereof, I have signed my 5.

name to this specification. 1 v

WILLIAM NELSON PARKES. I

